This invention relates to electrical connectors of the type having insertable and removable contacts. The invention is more particularly related to a means for the removable securing of an electrical contact retention device within an integral body of dielectric material. Additionally, a means for molding the integral dielectric insert with a core pin and core bushing is disclosed.
Electrical connectors generally include a plug and a receptacle, each of which has an insert of dielectric material within which electrical contacts are retained. The prior art under consideration addresses the insert means which were employed to secure electrical contact retention devices within a dielectric material and the means of molding these inserts.
Among the techniques often employed was the use of complex and intricate retaining mechanisms which were generally comprised of multiple pieces of dielectric material bonded together. When multiple pieces of dielectric are used, it is necessary to carefully seal the pieces together in order to eliminate the lower resistance paths and electrical breakdowns which occur between contacts along the interface of the pieces that form the retention clip insert. Examples of this method are disclosed in U.S. Pat. No. 3,727,172 and No. 3,638,165. The difficulties encountered with multiple pieces of dielectric bonded together to form an insert were partially overcome by minimizing the number of pieces of dielectric material required to fabricate an electrical connector insert. This technique is advanced in U.S. Pat. No. 4,082,398, assigned to the assignee of the present invention and incorporated by reference herein. Perhaps one of the most significant developments prior to this disclosure in the field of electrical connector retention means is found in U.S. Pat. No. 3,158,424. Among the teachings of this patent is the use of a flange, encompassing a full 360.degree., at the rearward edge of an insert passageway that is designed to hold an electrical connector retention clip within the bored section of an insert. This design, however, contains several drawbacks which become evident in the manufacture of the insert. It is taught that this insert can be molded with an annular member that is removable or dissolvable or otherwise disposable from the molded insert. Among the problems encountered in this method of manufacture is an inexactness in the length and positioning of the metal bushing being molded into the insert. After melting the bushing away from the insert, a standard length connector retention clip may not seat properly with the result that the entire insert must be scrapped. Another problem with this type of manufacturing method is that the metal bushings have to be cleaned thoroughly prior to molding the bushing into the insert. If any metal chips have not been cleaned from the bushings, they become molded into the insert and can cause electrical breakdowns within the insert. Another major problem with the use of metal bushings is that oxidation and static electricity are formed on the bushings. This results in obvious handling and molding difficulties.
The present invention eliminates the problems encountered with electrical failures within the inserts as well as those difficulties common to the manufacturing methods now employed.